1. Field of the Invention
The present invention concerns a system for supplying a vehicle internal combustion engine with fuel, comprising, in an inlet manifold, an inlet butterfly valve mounted so as to move under the action of a mechanical control device and fixed so as to move with the shaft of a movement regulating motor, the motor being fixed so as to move with the control device.
2. Description of the Background Art
In the case of a petrol engine, the speed of the motor is notably determined by the accelerator pedal, which acts on the inlet butterfly valve.
In order to function optimally, so as not to stall or cause excessive pollution, the engine must be supplied with a mixture of air and petrol at the required rate, remaining within well-defined proportions.
However, at throttle down, switching on an electrical appliance, such as an air conditioner, puts a sudden load on the engine, which may stall. In order to remedy this, it is known that an additional air inlet circuit can be provided. A computer for monitoring the engine speed controls, by means of a stepping motor, a needle regulating the additional circuit and prevents stalling by means of the corresponding input of air.
The document FR-A-2 599 805 discloses a supply system of the type mentioned above in which the shaft of the motor is fixed to the butterfly valve with respect to rotation and the associated stator is mounted so as to rotate and is driven by an accelerator pedal.
However, if the accelerator pedal is depressed or released abruptly, the engine is not able to function optimally. The present invention aims to resolve this problem.
To this end, the supply system of the invention is characterised in that a microprocessor is arranged so as to measure the movement of the regulating motor with respect to an idle position and to demand the rotation of its shaft according to the said movement.
Thus any movement of the control device which would cause the motor to leave its optimum range of functioning is compensated for by the action of the regulating motor, and a mechanical excessive-acceleration command is transmitted to the regulating motor in an integrated form, that is to say spread over time.
Advantageously, the microprocessor is arranged so as, in response to a movement of the control device, to limit the speed of movement of the shaft and to demand, if suck is the case, a complementary progressive movement of the latter.